Creating a slideshow

This is for Custom Loading Screen 1.5.5 for 1.12.2, rather than any older version.

1. In config/customloadingscreen.cfg Change S:screen_config to S:screen_config=config/slideshow
2. Create a folder config/customloadingscreen/
3. Add your slideshow images in config/customloadingscreen/ named slideshow_1.png, slideshow_2.png, slideshow_3.png, etc
4. Copy the contents of this file into a new file in config/customloadingscreen/slideshow.json.
5. Change any of the 4 constants at the top of the file to tweak the slideshow a little bit.